The present invention generally relates to paint that is washable from fabric and skin.
It is well known that a major deficiency of children's paints is their propensity to leave enduring stains on both skin and clothing. While permanence is a desirable characteristic of the so-called “permanent” paints, it is one of the most objectionable of properties for paints used by young children. Accordingly, much effort has been expended over many years by producers of these instruments to reduce or eliminate staining. This is attested to by the rather numerous offerings of so-called “washable” paints, which on close examination, are found to be removed either very poorly from fabrics that are typically used in children's clothing, removed poorly from skin, or have poor color saturation.
The majority of children's washable paints use pigments as the color source. While labeled as washable, washable paints using pigments will tend to permanently stain a variety of fabrics and other porous surfaces if the paint is allowed to dry.
In addition, some children's washable paints use acid dyes as the color source. While also labeled as washable, these paints will tend to stain skin and other porous surfaces within a few minutes of contact.
There are a number of commercially available additives that are known to increase the washability of acid dyes from skin and other porous surfaces.
One strategy to improve washability is to use low levels of colorants which give lighter color shades and less opacity on paper. Because there is less color in the paint, it is easier to remove from skin and fabric, but results in lower saturation paints. Polymeric colorants may also be used in washable paints. Some polymeric colorants are described in U.S. Pat. No. 5,043,013.